Punch-removing device



Feb. 24, 1953 A. BOLDUC 2,629,274

PUNCH-REMOVING DEVICE j Filed April 19, 1948 2 SHEETS-SHEET 1 INVENTOR. fl/Zerz .5 o/au 0.

3 .45 I l f M.

1953 A. BOLDUC 2,629,274

PUNCH REMOVING DEVICE Filed April 19, 1948 2 SHEETS-SHEET 2 INVENTOR. E- fizz; flozduc.

Patented Feb. 24, 1953 UNITED STATES. PATENT OFFICE 2,629,274 PUNCH-REMOVING DEVICE Albert Bolduc, Detroit, Mich.

Application April 19, 1948, Serial No. 21,903

4 Claims.

This invention relates to new and useful improvements in pulling devices for removing punches, bearings and the like from their holders or retainers.

In conventional punch presses, the punches are carried by a hydraulically or mechanicallyoperated platen. The platen frequently is quite large, and a large number of punches may be pulled from the retainers when they are withdrawn from the work.

Also, it is conventional practice to provide a stationary stripper plate in front of the platen which holds the work down when the platen is raised to remove the punches. The punches operate through holes in the stripper plate, and when the platen is retracted the punches are disposed entirely behind the plate. The large area of the platen and the fact that the punches are disposed behind the stripper plate when the platen is retracted makes it very difficult to remove the punches. Also, it will be readily apparent that if a punch is broken, it is even more difficult to remove than an undamaged punch,

since itcan be reached only through the hole in the stripper plate, unless the latter or other parts of the machine are disassembled. In this connection it should be noted that the travel of the platen is relatively small, so that the maximum space between it and the stripper plate is always relatively small.

Heretofore removal of punches has been a difiicult and arduous task. The present invention is concerned with a device for removing punches easily and expeditiously from their retainers.

Ball bearings and the like frequently are mounted with the outer races thereof press fitted into suitable bearing retainers. These bearings frequently are difficult to remove, and this is particularly true if the bearing retainer is cupshaped or otherwise closed behind the bearing.

The present invention also is concerned withmeans for removing bearings from their holders or retainers.

An important object of the present invention is to provide a pulling device that is readily insert-,

2 ible through and into relativelysmall openings to grip an object to be removed.

Another object of the invention is to provide a pulling device having a gripping element which acts positively and. quickly to, engagean object to be removed and which effectively holds such object during removal thereof.

Still another object of the invention is to provide a pulling device, which fixedly engages the object to be removed and which clamps the object in such manner as to resist any tendency to pull off of-the object.

Yet another object of the invention is to provide a pulling device which is particularly adapted for removing punches and which ineludes means for, releasing the ball detent from the punch before the latter is removed from the punch retainer.

A'further object of the invention is to provide a pulling. device having novel means permitting easy manual operation and manipulation thereof.

Other objectsand advantages of the invention will be apparent during the course of the following description. H

In the drawings forming a part of this specification and wherein like numerals are employed to designate like parts throughout the same:

Fig. 1 is a longitudinal sectional view of a puller embodying the invention adapted for pulling punches or the like from their retainers, said figure showing the puller applied to a punch and illustrating the relationship between the punch and the puller with adjacent parts of a. punch press;

Fig. 2 is an enlarged, fragmentary view showing the portion of Fig. 1 enclosed in the circle 2; Fig. 3 is an enlarged, fragmentary, transverse sectional view taken on the line 3-3 of Fig. 1; Fig. 4 is an enlarged, fragmentary, transverse sectional view taken on the line 4-4 of Fig. 1;

. puller being shown in section for clearness of illustration; i i

Fig. 6 is an.enlarged, fragmentary, transverse sectional view. taken on the line 66 of Fig. 5; and M i Fig. '7 is an.enlarged, transverse sectional view taken on. the line 1--'! of Fig 5.

The form of the invention adapted primarily to the inner member 30'.

3 for pulling punches or the like shown, and particularly in Figs. 1-4, is first described.

A punch is indicated at l6 and is shown mounted in the usual punch retainer I2 which in turn is carried by the usual movable platen I4. A ball detent i 6 within the punch retainer i2 is pressed into a recess it inside of punch ID by a spring 29. The punch l8 fits tightly in the punch retainer l2 and the ball detent [6 looks the punch in the retainer. 7

In order to remove the punch in from the retainer l2, it is necessary to push the ball detent l upwardly away from the punch and then pull the punch downwardly out of the retainer. Usually an elongated rod or pin is applied against the ball detent !5 through an opening 22 in the punch retainer l2.

A stationary stripper plate 24 is positioned be low and parallel to the platen l4, and the punch ill operates through a hole 26 in the plate. At one side of the hole 26 and in register with the hole 22 is a lateral recess 28 which permits a pin to be. inserted upwardly through the stripper plate and into the hole 22 to disengage the ball detent i6 from the punch [0.

The device for removing the punch f0 comprises inner and outer telescoping members 30 and 32. The outer member 32 is insertible through the opening 26. and the inner member 3!! is adapted to fit snugly over the punch Hi, as shown in Fig. 1. Resilient, radially flexible fingers 34 are provided at the forward end of the inner member 30, and the outer member 32 is formed with an internal cam surface 36 which presses the fingers 34 radially inwardly against the punch I!) when the inner member is advanced axially in the outer member. In this connection it will be readily apparent that the fingers 34 can be released from the punch HI merely by retracting the inner member 30 in the outer member 32.

Anv suitable means may be employed for moving thev inner member 3!) back and forth in the outer member 32. In the form of the invention here shown by wa of illustration, I mount an Allen-head screw 38 for free rotation in the rearward portion of the outer member 32. The screw 38 extends axially through the member 32 and the projecting inner end thereof is threaded in- As shown in Fig. 4, the screw 38 is located eccentrically with respect to the inner member 30 so as to prevent the latter from rotating in the outer member 32 during operation of the screw. The screw 38 is rotated by a conventional manually operable Allen wrench 49. r

A handle 42 extends transversely through the outer member 32 and provides a convenient.

handgrip for pulling the punch from the punch retainer !2 after the device has been clamped solidly on the punch.

In order to release the ball detent 6; a collar 44 is mounted for sliding movement on the outer member 32, and this collar carries a pin 46 which extends forwardly alon side the outer member.

7 When the device is applied to the punch ID, the

pin 46 extends throu h the recess 28 and the forward terminal portion thereof is disposed in alignment with the hole 22. When the collar 44 is advanced from the full-line to the dotted-line position in Fig. I, the pin 46 is inserted through the hole 2?. and forces the ball detent l6 from the full-line to the dotted-line position to release the punch ID. The punch may then be readil removed from the retainer l2 by pulling downwardly on the handle 42. Pin 4.6 holds th ball detent it away from the punch Ill during initial downward movement of the latter and until the recess |8 moves downwardly into a position where it can no longer be engaged by the detent. The detent I6 may then be released by pin 46 without appreciably affecting further withdrawal of the punch.

More specifically the inner member 30 here shown. has an annular wall portion 48 and an integral, relatively thicker transverse portion 50 at the rearward end of the annular wall 48. The flexible fingers 34 preferably are formed integral- 1y with the annular wall portion 48. In the drawings the fingers 34 are defined by a plurality of longitudinal slots 52 which extend from an intermediate point in the wall portion 48 axially through the forward end thereof. The terminal portions of fingers 34 are formed with tapered external surfaces 54 and the fingers preferably are tapered to a relatively thin edge, as perhaps best shown in Fig. 2. According to conventional practice, the rearward portion 56' of the punch It is somewhat larger in diameter than the forward work-engaging portion 53 thereof, and the inner surfaces of fingers 34 preferably are offset, as at fifl (Fig. 2), to compensate for this difference in diameter.

In use, the fingers 34 are supported internally by the punch ill and externally by the outer member 32; consequently, they may be made relatively thin without danger of breakage. It is an advantage to be able' to use relatively thin metal fingers, since they act positively and quickl'y to engage the punch I0. Further, they are more flexible and sensitive and therefore are less likely to slip on the punch when the latter is being pulled from the retainer I2. It is essential that all parts of the device he maintained as thin as possible, since the radial dimension between the punch l0 and the wall of opening 26 is relatively small. One of the primary problems here is to provide a device that will enter the very small space which is available and at the same time is strong and rugged enough to serve its intended purpose.

The outer member 32 comprises a forward skirt portion 62 and a rearward shank portion 54. The skirt portion 62 is generally cylindrical in transverse section and fits snugly but slidably over the inner member 30. Also, it will be observed that the skirt portion 62 is somewhat longer than the inner" member 36 so that the latter is free to move a substantial distance axially therein. As suggested, the forward terminal portion of the skirt 62 is formed with an internal; forwardly tapered, annular cam surface 36 which engages the tapered. external surfaces 54 of fingers 34 when the inner member 30 is advanced by the screw 38 to force or flex the fingers into pressed engagement with the punch [0. When the inner member 313 is retracted in the outer member 32, the external cam surfaces 54 disengage the internal cam surface 36, and the fingers 34 are permitted to expand sufliciently so that they can be easily and quickly fitted over the punch H1.

The rearward shank portion 64 preferably is relatively elongated and conveniently may be made approximately as long asthe forward skirt portion 62. Also, the shank 64' preferably is somewhat smaller in diameter than the skirt portion 62 in order to bring the pin 46 as closely as possible to the skirt. A bore 66 extends axially through the shank 64 to accommodate the screw 38, and the rear terminal portion of the bore is countersunk to provide a radial seat :63 for the enlarged head portion Id of the screw.

The handle 42' extends transversely through the shank portion 64 behind the head and thus serves as a retainer for the screw 38.

The wrench 40 is generally L-shaped, according to conventional practice, and a portion 12 thereof extends into the socketed head 10 through a transverse hole M in handle d2. According to the present invention the portion of the wrench which extends through handle 42 is formed with an annular peripheral groove 16, and the handle is peened over to provide an annular bead 13 which projects into the groove 13. The annular head 18 effectively fastens the wrench 4|] to the handle 42 but permits the wrench to be freely rotated to operate the screw 38.

In operation, the device is first slipped over the punch It, as shown in Fig. 1, with the inner member 30 retracted in the outer member 32. The wrench 40 is then actuated manually to rotate the screw 38 so that the latter advances the inner member 39 to press the flexible resilient fingers 34 against the internal annular cam surface 3'6. .As the inner member advances, the flexible fingers 34 are wedged solidly between the cam surface 35 and the punch Ill. An efiective grip is thus afforded between the fingers 34 and the punch Ill so that the device can not be pulled axially off the punch. The ball detent I6 is then released by manipulating the collar 44 and pin 46 in the manner hereinabove described, and a downward pull is exerted against the handle 42 to pull the punch It from the punch retainer l2.

The instant device is effective for removing either damaged or undamaged punches. A punch very seldom, if ever, breaks within the retainer I2. Usually there is a stub which projects from the retainer, and this stub can be engaged by the device for removal in the manner hereinabove described.

The bearing puller shown in Figs. 57 is generally similar to the form of the invention first described. However, in the latter construction, the device is adapted to be expanded instead of contracted against the element to be removed.

The bearing puller here shown by Way of illustration comprises an inner member 80 in the form of an elongated generally cylindrical plug, and an outer member 82 having a forward sleevelike portion 84 which fits snugly around the inner member 80. The rearward portion of outer member 82 is in the form of an elongated, generally cylindrical shank 86. Mounted for free rotation in the shank 86 is an Allen-head screw 38. The head of screw 88 seats forwardly against an annular shoulder 90, and the threaded shank portion thereof is screwed axially into the inner member 80. A handl 92 extends transversely through the shank 86 behind the screw 88, and. an Allen wrench 94 extends diametrically through the handle 92 into the socketed head of the screw. The wrench 94 preferably is provided with an annular, peripheral groove 85. and the handle 92 preferably is peened to provide an annular bead 9B which enters the groove to hold the wrench 94 associated with the screw 88. A guide pin I00 embedded in the shank #26 projects forwardly into a guideway I92 in the inner member 80 to prevent relative rotation between the latter and the outer member 82.

Except for the specific means for preventing relative rotation between the inner and outer members 80 and 82, the above construction is tion 84 through the forward end thereof.

generally similarto the form of the invention first described. This form of the invention differs primarily from the first form in that the inner member is formed with a fiared terminal portion which provides an external, annular cam surface I04, and the outer member 82 is provided with overlying terminal fingers it. In the form of the invention here shown, the fingers 106 are formed integrally with the outer member 82 and are defined by axial slots I98 which extend from an intermediate point in the skirt por- The inner surfaces of fingers [B5 are longitudinally tapered, and the taper angle preferably complements or coincides with the angle of cam surface I04.

In operation, the fingers I66 may be flexed radially by retracting the inner member lid axia1 ly in the outer member 82. As the inner member 80 moves rearwardly or inwardly, the cam surface it presses against and expands the fingers Hit. Conversely, the flexible fingers we may be contracted from an expanded position merely by advancing the inner member $13 in the outer member 82. It will be readily apparent that the inner member may be moved back and forth in the outer member by rotating the wrench 9 5.

In Fig. 5 I have shown the device associated with a ball bearing 1 le of conventional design which is disposed within a conventional bearingreta-iner H2. For the purpose of this discussion, it is assumed that the outer race of the bearing 1] 0 is press fitted in the retainer l i2 and that it is desired to remove the bearing from the retainer.

In use, the device is inserted into the inner race of the bearing H!) with the inner member 80 fully advanced and the fingers i as contracted. The outer member 82 should fit the inner race of the bearing snugly but slidably. The inner member80 is their retracted in the outer member 32 by rotating the wrench 94 and the screw 88. As the inner member as retracts, the cam surface I04 is tightened against the fiexible fingers Kit to expand the latter solidly against the inner race of the bearing. When the inner member lid has been retracted as far as possible, the fingers I8 3 are wedged solidly between the bearing and the cam surface I04, and the bearing may be re moved from the retainer H2 by pulling on the handle 92.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the size, shape, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the appended claims.

Having thus described the invention, I claim:

1. A device for pulling a punch element out of a punch retainer through an opening in a stripper plate comprising telescoping inner and outer sleeve members having forward terminal portions insertable through the opening and over the punch element, the forward terminal portion of said outer sleeve member formed with an internal tapered cam surface and said inner sleeve member having axial slots extending from an intermediate portion in the sleeve member to the forward end thereof to provide flexible fingers;

means for moving the inner sleeve member axially in both directions in said outer sleeve member so that the resilient fingers can be contracted and held solidly against the punch element by advancing the inner sleeve member in the outer 7 sleeve member to press the ends of said resilient fingers against said cam surfaces and so that the resilient fingers can be expanded to release the punch element by retracting the inner sleeve member in the outer sleeve member, the lastmentioned means comprising a manually oparable screw mounted to rotate freely in said outer sleeve member and threaded into said inner sleeve member; and including means for holding said screw against axial movement relative to said outer sleeve member, whereby rotation of said screw moves the inner sleeve member axially in said outer sleeve member.

2. The combination as set forth in claim 1 wherein said screw is eccentrically received by said inner sleeve member, so that the inner sleeve member will not be rotated in said outer sleeve member by operation of said screw.

3. A device for releasing the ball detent which conventionally holds a punch element in a punch retainer and then pulling the punch out of the punch retainer through an opening in a stripper plate comprising telescoping inner and outer sleeves having forward terminal portions insertable through the opening and over the punch element, a collar slidable on said outer sleeve; a pin carried by and movable with said collar, said pin extending forwardly alongside the outer sleeve and engageable with the ball detent when the inner sleeve is inserted over the punch element so that the detent can be released from the punch element by advancing the collar on said outer sleeve, an internal annular cam surface at the forward end of said outer sleeve tapering toward the end of the sleeve; contractible resilient fingers at the forward end of said inner sleeve engageable with and contractible by said internal cam surface; and means for advancing and also retracting the inner sleeve in said outer sleeve so that the resilient fingers can be contracted and held solidly against the punch element by advancing the inner sleeve in the outer sleeve to press the ends of said resilient fingers against said internal cam surface and so that the resilient fingers can be expanded to release the punch element by retracting the inner sleeve in said outer sleeve to disengage said"iiexible. ijingers from said internal cam surface.

4. A device comprising inner and outer mem here, one of said members having flexible resilient fingers and the other of the members having a cam surface coactive with said fingers upon relative axial movement between said memhere to flex the fingers radially, an Allen-head screw extending axially through the outer memher and threaded into said inner member a sub stantial distance behind said fingers and said cam surface; a handle extending transversely through the outer member behind said screw, said handle extending across the head of the screw and holding the latter against axial movement in one direction; an Allen wrench-having angularly related portions, one of said portions extending axially into said outer member and transversely through said handle into the socket head of said screw, said wrench being freely rotatable in said outer member and in said handle to rotate said screw; an annular peripheral groove in the portion of said wrench within said handle; and a radially projecting stop means on said handle extending into said radial groove to prevent withdrawal of said wrench from said screw.

ALBERT BOLDUC REFERENCES CITED The following references are of record in the file of this patent.

UNITED STATES PATENTS Number Name Date 1,227,877 Brisbin May 29, 1917 1,464,693 Campbell Aug. 14, 1923 1,710,835 Nielsen Apr. 30, 1929 2,373,064 Stelzer Apr. 3, 1945 2,4=13,944 Bolduc Jan. 7, 1947 2,421,181 Batchelder May 27, 1947 FOREIGN PATENTS Number Country Date 2,730 Great Britain Feb. 4, 1909 

